bi·ped·al·ism \(ˈ)bī|pedəlˌizəm also -|pēd- sometimes ˈbipəd-\noun orbi·pe·dal·i·ty\ˌbīpə̇ˈdaləd.ē sometimes ˌbip-\ (pluralbipedalismsorbipedalities) : the condition of having but two feet or of using only two for locomotion if more are present < the bipedalism of some desert lizards >